READ MY COMMENT BELOW REGUARDING THIS REPORT BEING "RESOLVED"
Endermen Water Bug- https://www.mediafire.com/file/rtl1nxwunylndpg/Minecraft_Enderman_Water.mp4/file
Endermen often walk into water repeatedly after being damaged by water.
Endermen seem to treat water very weird almost like the water is an entity itself...
I've encountered this bug on Nintendo Switch, Windows 10, and Xbox One and I bet it's across all platforms.
- Has been reported on android via comment